| keb | Kaspersky Anti-virus Virus Bases Data |
| kgb | KGB Compressed Archive |
| kge | KGB Archiver Encrypted |
| knar | KNIME Workflow Archive |
| kodi | Kodi Update Data |
| kry | Krypter Encrypted Data |
| ksp | KeyShot Package |
| kva | KVIrc Compressed Archive |
| kwt | KVIrc Theme Pack |
| kz | KuaiZip Compressed File |
| lal | Liberkey Core Update File |
| lbf | LG Phone Backup Archive |
| lbr | LU Library Archive |
| lcb | Living Cookbook Backup |
| lg | Arhangel Compressed Archive |
| lgbackup | LG G7 Phone Backup Archive |
| lgu | LG Windows CE Device Firmware Update |
| lha | LHarc Compressed Archive |
| lharc | LHarc Compressed Archive |
| lhw | LhWarp Compressed Archive |
| lhz | LHarc Compressed Archive |
| liz | Liberty Instruments LAUD Program Update |
| lja | ljArchive Archive |
| lks | Liberkey Installation Package |
| lnx | Commodore 64 Lynx Archive |
| lok | WinGuard Pro Lok Archive |
| lou | Liquidware LouZip Archive |
| lpaq | LPAQ Compressed Archive |
| lpaq1 | LPAQ1 Compressed Archive |
| lpaq5 | LPAQ5 Compressed Archive |
| lpaq8 | LPAQ8 Compressed Archive |
| lpk | Lazarus Package |
| lpkg | Liferay Package |
| lqr | Squeezed LBR Archive |
| lrp | Linux Router Project Package |